Legal Distinctions Between a Name Change and an Alias. A legal name change requires a formal court process to alter one’s name on all legal documents. Governed by state laws, this process typically requires a valid reason, such as marriage or divorce. Court approval results in an official change that affects government-issued identification ...

A legal name is the name that is officially recognized by the government and used in legal documents, like birth certificates or driver's licenses. An alias is an alternative name that someone chooses to use, which may not be recognized legally.

I don't think you need to legally file anything in order to use an alias or pseudonym. However, if you anticipate that your alias will become famous enough with respect to the services/goods you are providing, then it might make sense to file for trademark registration.

The term ‘alias’ typically refers to any name that an individual uses other than their legal name. Aliases can be used for various reasons, including privacy protection, career needs, or personal preference.

An alias describes another legal name that the individual goes by, or has previously gone by, for example, a name before a marriage, or a legal name that does not include a middle initial. On the other hand, an alias is just a name that has not been legally assigned, but is used.